In belt/pulley assemblies, it is important to obtain the proper tension for the system to function properly. The proper tension is necessary to avoid slipping and to prevent undue friction on the bearings or shafts holding the pulleys. If there is too little tension, the belts can slip, providing an inefficient and inaccurate drive train. If the tension is too great, excess friction and heat can develop, resulting in a shorter life for the belt, pulley bearings, and other parts associated with the belt/pulley assembly.
Typically, in adjusting the tension in a belt pulley system, the belt would be tightened until it felt right. This required a degree of guesswork, in combination with experience, to obtain an approximation of the proper tension. The deflection, with a known force, of the belt at the center of the belt span between the pulleys is also often used to approximate the proper tension. These adjustment techniques are inaccurate and difficult to accomplish. Additionally, a working but less than optimal tension is often obtained in a belt/pulley assembly using these techniques. This resulted in inefficiencies which cause subsequent problems, such as slipping, wear, or worn bearings. Also, in order to adjust the tension in a belt, it is often necessary to use two hands, or even the assistance of another individual. One of the pulleys in the belt/pulley assembly has to be loosened, moved, and held in position and resecured at the same time while maintaining the desired tension on the belt. This is often difficult to accomplish and usually after resecuring the pulley the tension in the belt is not correct.
While these techniques of tensioning a belt/pulley assembly have proven to be adequate for some applications, they are unacceptable for others, especially precision mechanisms.
Therefore, there is a need for a device that accurately and easily applies the proper tension to a belt/pulley assembly. Therefore, resulting in increased efficiency and life of the belt/pulley assembly.